Method of scanning images in television



p 1933- R. BARTHELEMY ET AL ,928,553

METHOD OF SCANNING IMAGES IN TELEVISION Filed Sept. 12, 1930 2Sheets-Sheet 1 Ni .1 Fl

Se t. 26,1933. R. BARTHELEMY ET AL 1,928,553

' METHOD OF SCANNING IMAGES IN TELEVISION Filed Sept. 12, 1930 2Sheets-Sheet 2' Patented Sept. 26;, 1933" r l i I 1,928,553 I METHOD orSomme nwaons IN I 'rELnvrsroN Rene Barthelemy, Fontenay aux Roses, andJean lLe Duc, Vancresson, France, assignors to Compagnie pour'laFabrication des Compteurs et Materiel dlflsines a Gas, Seine, France, ajoint-stock company of France Application September 12, 1930, Serial No.

481,493, and in France September 25, 1929 4 Claims. (or. 178-6) In thepresent systems usedfor television, the These discswill be homothetic.As shown in image is scanned at the transmitting end and Fig. 3, theholes are located along two semireconstructed at the receiving end bymaking use spirals of opposite pitch.- I of two perpendicular movements,one at high fre- A particular case is provided by telecin'ema- 5 quency,400 to 500 cycles per second and the tography where the continuousdisplacement of '55, other at low frequency, to cycles per second. thefilm at the transmitting end calls for discs The low frequency scanningof thefield produces having different perforations at the transmittingon the eye the impression that the background and receiving ends, forscanning in the two/opof the image is continually moving in a fixeddiposite directions. This solution is however pracio rection, namelythat in which the image is being ticable and its only drawback is thatitrequires 60," i

scanned. an additional scanning disc at thetransmitting The presentinvention isconcerned with a sysend. In this case, the holes will bedistributed tem that obviates this drawback, and gives the over twosemi-spirals not only of differentkbut observer an impression offixedness of the backalso of contrary pitch. The receiving. disc will 1ground of the reconstituted image. not be changed whether television or"telecine- "(s,

According, to the present invention, the image matography be involvedand this is the essential is scanned twice, in opposite directions, inless practical condition. y y l I a T 6 o a S fi b at the sending and atv The same disc can likewise be used for send I the receiving end inorder toavoid the illusion of mg cinematographic and lined images oreven the displacement of the background of theimage for the televisionof animated subjects andthe in a fixed direction. teleprinting ofdocuments; to this end; in the I The invention has been illustrateddiagramcase of cinematography and even in the case of matically in. theaccompanying drawings, in teleprinting, an intermittent movement will bewhich: I imparted to the film as is accomplished in or- Fig. 1 shows theimage being scanned in one dinary moving picture technique andjadvantagedirection and f v c will be taken of theinstant ofdwell ofisaidfilm Fig.2 shows the image being scanned in the opto scan the image just as if afixed image were posite direction. A concerned. v v Fig. 3 shows ascanning disc the holes of which The novel result will be to simplifythe trans- 3 lie on two semi-spirals. mitting mechanism by making itmore general Instead of sending out successively the contiguin characterand by increasing the rapidityof ous modulated luminousbands resultingfrom the the teleprinting processes. l ordinary scanning operation, onlyhalf these Y We claim: p bands, for x mpl r n in n y ne 1. A method ofscanningimages in television, 351321101 Out of two- T total Scanning Opon in telecinematography and the like, which consists 85.,- thedirefltiOn f1 (Fig 1) W e accomplished in in scanning one in every twobands of a series of" half the usual time and a surface of constantadjacent bands, of an image and traversing said illumination at thetransmitting end will be repreimage from end to end in a directional;right sented by a plurality of dark bands alternating angles to saidbandshalf the lines'of theirnage 4 with light bandsas shown in Fig. l.beingthus scanned in a very short timeless than 9.0;

The oth half of the bands Will be xp o y one twentieth of a second, thewhole image being Sca i the'image in the pp t d tion, scanned in lessthan one tenth of a second,iand i. e. f2 and gives the resultillustrated in Fig. 2. in then traversing said image in the opposite Thesuperposition of the two images in less direction and scanning thosebandsnot'scanned 45 t 1% 86001161, gives the u image i which during thefirst traverse of theimage. 95. the two impressions of displacement arein op- 2. In a television apparatus, a scanningdisc position and cancelout on the eye of the observer. having not more than two series of holeslying This will be readily carried into effect by suitalong twosemi-spirals of opposite and "contrary ably locating the holes both inthe discs at the pitch and so arranged that the bands scanned 50'sendingand in the ones at the receiving end. through the holes ofonesemi-spiral alternate in position with those scanned through the holesof the other spiral.

3. The method of scanning a picture in a television system comprisingscanning certain of the 5 picture elements throughout the whole picturein one direction and thereafter scanning the other elements in anotherdirection.

4. The method of scanning a picture in a tele-

